This investigation seeks to develop stress resistance theory. Models that suggest that personal and social resources will aid stress resistance to the extent that they fit external demands or behavioral intentions will be compared. In addition, a new stress theory that suggests that people employ resources to offset loss engendered by stressors will be examined. This latter model also argues that 1) the use of weak personal and social resources in the service of stress resistance, further taxes these resources and results in their depletion and 2) that either personal or social resources may alone be sufficient (i.e., both are not necessary) if one of the two is weak. How self-esteem and social support interact to affect psychological and physical health outcome following stress exposure will be investigated in order to examine these models. In addition, how these factors affect health behaviors that lead to different health outcomes will also be studied. The concept of social support will also be broadened by examining more fully the characteristics of support providers (i.e., the social ambience). Exploring these questions will contribute to a more theoretical understanding of he underlying factors in stress resistance. These questions will be addressed in the context of a study of 500 low medical risk pregnant women. Data will be obtained both from women and each woman's most significant other during three interviews occurring during the 2nd trimester, 8 weeks prior to scheduled partum and 8 weeks post scheduled partum. Clinical diagnostic data concerning depression and complications of pregnancy will be obtained from psychologists and medical personnel, respectively. Data analyses will address causal relationships among the variables and the fit of specific resources with specific stress- related demands.